The goals ofthe Clinical Core are to provide a uniform approach to subject recruitment and charactehzation, and to provide clinical samples forthe individual projects. Aim 1. Clinical and human subjects support for individual projects Task 1. We shall prepare and maintain protocols and consents interfacing with the IRB, maintaining and stohng records, creating and filling out the clinical research forms, creating and maintaining a manual of operation for handling and disthbuting samples, and assunng training of study personnel who have direct patient contact. Task 2. We shall recruit a sufficient number of patients and healthy volunteers for the proposed immunological studies. Task 3. We shall clinically evaluate all patients and determination of disease activity. Clinical assessors will be kept blinded to investigative laboratory studies until all experimental data has been entered into the webbased data management system. Task 4. We shall coordinate specimen handling and the disthbution of samples to laboratory investigators. Laboratory investigators will be kept blind to subject group until all experimental data has been entered into the web-based data management system. Task 5. We shall draw penpheral blood specimens and coordinate all other procedures including bone marrow and synovial biopsies. Task 6. We will evaluate a interferon signature, biological activity of type 1 interferon, IFN regulated chemokines, and levels of BLyS and APRIL, Aim 2. In vivo labeling In cooperation with the GCRC deutehum-labeled glucose will be used for the in vivo labeling and collect penpheral blood specimens for ex vivo analysis of lymphocyte subsets. Individual projects will then isolate lymphocytes subsets of interest. A subcontract with the University of California at Berkley will measure incorporation of deuterium into lymphocyte subsets using mass spectroscopy.